\begin{frame}{DFAs as Transition Graphs}
  \begin{block}{}
    A DFA can be visualised as a \emph{transition graph}, consisting of:
    \begin{itemize}
      \item \emph{states} are the \emph{nodes} of the graph
        \begin{itemize}
          \item \emph{starting state} indicated by an \emph{extra incoming arrow}
          \item \emph{final states} indicated by \emph{double circle}
        \end{itemize}
      \item \emph{arrows} with labels from $\Sigma$:\; \alert{$q \stackrel{a}{\to} q'$ if $\delta(q,a) = q'$}
    \end{itemize}
    %We have an \alert{arrow from $q$ to $q'$ with label $a$ if $\delta(q,a) = q'$}.
  \end{block}

  \begin{exampleblock}{} 
    \edfa
    is visualised as the transition graph
    \begin{center}\vspace{-1.5ex}
      \input{tikz/dfa_even_bs.tex}
    \end{center}    
  \end{exampleblock}
  \bigskip
  
%   \begin{exampleblock}{}
%     \begin{minipage}{.2\textwidth}
%     $\Sigma=\{\,a,b\,\}$\\[14ex]
%     \end{minipage}
%     \begin{minipage}{.79\textwidth}
%     \centering
%     \input{tikz/dfa2.tex}
%     \end{minipage}
%   \end{exampleblock}
\end{frame}